An automated, Robotic Biosensor for the Electrochemical Detection of E. Coli in Water☆

Abstract Escherichia coli are indicator bacteria for fecal contamination in water. The goal of our study was the implementation of an assay for voltammetric detection of E. coli into an automated instrument. Furthermore, this electrochemical biosensor works as a stand-alone instrument with on-line data transfer to monitor and control the water quality and to enhance treatment measures. The device performs automated water sample filtrations, followed by addition of growth media to the filter unit. After an incubation step, a defined sample aliquot is transferred on a screen printed electrode. The result of the electrochemical measurement indicates the presence of E. coli . The device output was compared with laboratory analysis. With the designed instrument it was possible to detect 5 colony forming units (CFU) of E. coli in 5 ml within 18 hours.